"Step-by-Step" Automatic Switching System (H-type) (1926)

This was a "step-by-step" automatic switching system developed by German company Siemens & Halske, in which switches were operated corresponding to each digit on a telephone dial. It was first used in Japan in 1926, at the Yokohama Central Telephone Exchange and Chojamachi Branch.
Fujitsu had produced this system since the time of its establishment, and it was one of its main products for over 30 years until the 1960's.